When the visual conditions are poor, especially in the dark, it is the task of the headlamps of a vehicle to illuminate the environment in front of the vehicle in the driving direction, in particular the roadway. In addition, the headlamps serve to identify the vehicle to other road users.
For the light emission in the driving direction, it is conventional to provide headlamps which are able to offer a low beam functionality and a high beam functionality. The high beam functionality produces a very comprehensive illumination of the environment. However, it has the disadvantage of blinding other road users, in particular the drivers of vehicles driving ahead and of vehicles approaching from the opposite direction. The low beam, on the other hand, makes it possible to generate a light pattern that does not blind other road users, but the illumination of the environment is much lower than in the high beam functionality. Due to the very high traffic densities that have developed in the meantime, the high beam functionality can be used only rarely nowadays. As a consequence, headlamp systems are needed which offer better illumination than the conventional low beam functionality, but which do not blind other road users in the manner in which the high beam functionality does.
One method for controlling a headlamp system for a vehicle is described in German Published Patent Application No. 10 2007 045 150. In this case the headlamp system includes two headlamps, which are situated at a distance from each other and emit a combined light beam in order to generate a total light pattern. In addition, the headlamps are equipped with a diaphragm array, whose position is variable in order to modify the total light pattern. In the method, a road user is detected in the direction of the light emission of the headlamp system. If such a road user has been detected, the position of at least one diaphragm array is modified such that a center region having a lower illumination range, as well as side regions, which are adjacent to this center region and have a greater illumination range, are formed in the total light pattern on both sides in the direction of the detected road user. The illumination range in the center region, in particular in the direction of the detected road user, is controlled as a function of the vertical angle, that is to say, the distance of the road user. The light pattern is generated exclusively by modifying the position of the diaphragms of the diaphragm array, and possibly by pivoting the light emission direction of the headlamps about a vertical axis.
German Published Patent Application No. 10 2007 028 658 describes another method for controlling a headlamp system of a vehicle. In this case the headlamp system has a right and a left headlamp unit, both being equipped with separate headlamps for a low beam and a high beam light. In the method, a road user is detected in the direction of the light emission of the headlamp system. Once such a road user has been detected, the light pattern generated by the headlamps for the high beam is modified with regard to the lateral illumination, whereas the light pattern for the low beam produced by the separate headlamps remains unchanged.
Finally, a system for generating a light bundle in the movement region in front of the vehicle is described in German Published Patent Application No. 10 2007 040 042. The system is made up of a headlamp having an LED field provided with a plurality of light diodes, which are electrically controllable individually. In addition, the system has an object detection device for detecting objects in the vicinity of the motor vehicle, and a position determination device for determining the position of a detected object in relation to the motor vehicle. In this system the individual light diodes are controlled such that a limit value for a luminous intensity in the region of a detected object is not exceeded.